1. Scope of Invention
This invention relates generally to plumbing vent stacks that extend above a roof of a building for venting sewer gas, and more particularly for protecting the weatherproofing lead cover installed over the tubular vent stack.
2. Prior Art
A plumbing vent stack protrudes through a roof deck and is necessary to vent and disperse sewer gases from each sewer trap in a building or dwelling. To weatherproof this plumbing stack, a cover, formed of substantially lead material and having a tubular upright member connected to a flat flange, is fitted over the plumbing vent stack. After this weatherproofing cover is fitted over the vent stack and permanently secured to the roofing deck, the tubular portion, having a length substantially longer than that of the protruding vent stack, is manually hammered and forced over the distal end of the vent stack and down thereinto to effect a complete weatherproof sealing against wind and rain into the building around the vent stack.
Applicants are building contractors and have encountered situations wherein the outer lead cover has been chewed and even eaten away in parts by rodents such as squirrels and rats which easily gain access to the roof and to the cover over the vent stack. Of course, if the lead cover is chewed sufficiently to form a hole, the weatherproofing integrity is substantially compromised and the entire lead cover must be replaced or the hole effectively patched.
In addition to these rodents having access to the roof area, other critters such as snakes, birds, roaches and other larger bugs likewise may find their way to this area of the roof and into the vent stack. Routinely, such unwanted critters manage to climb down the vent stack, through the sewer trap and into the dwelling through a toilet, sink or drain area. Nests and dead animals trapped in the vent stack will also cause obvious problems.
Applicants are aware of a number of prior art devices which are intended to in some fashion enhance the basic function and structure of a conventional vent stack as follows:
U.S. Pat. No. 5,694,724 issued to Santiago PA1 U.S. Pat. No. 4,399,743 issued to Izzi PA1 U.S. Pat. No. 4,206,692 issued to Johnston PA1 U.S. Pat. No. 3,797,181 issued to Nievelt PA1 U.S. Pat. No. 4,442,643 issued to Stadheim
Specifically, the Stadheim '643 reference teaches an insulating sleeve for preventing interior frosting of the vent stack during colder winter months. The Nievelt '181 patent teaches a very complex structure for weatherproofing a roof vent pipe having molded inner and outer sleeves for encapsulating the upper end of the vent pipe. This device appears to be intended to fully replace the conventional lead cover above described.
Johnson, in U.S. Pat. No. '692, teaches a vent stack cover formed in the flat and manually manipulable into a shape which attaches over the distal open end of the vent pipe for preventing debris from entering the vent pipe itself. The Izzi invention in U.S. Pat. No. '743 teaches a cap which is installable over the distal open end of the vent pipe which includes a vandalism proof attaching means therewith.
The vent pipe cover invented by Santiago in U.S. Pat. No. '724 also teaches a plumbing vent stack cover or guard which replaces the conventional lead cover and which is molded of plastic in one piece to perhaps more effectively accomplish the purposes of the lead weatherproofing cover.
However, where a conventional lead cover is utilized, this mode of weatherproofing still remaining the most popular among building contractors to date, no consideration has been given to both prevent rodents from chewing and attacking the weatherproof integrity of the lead cover and also to prevent such rodents and other larger critters such as snakes, roaches and the like from entering into the vent stack itself.